838 research outputs found

    Computer program for compressible flow network analysis

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    Program solves problem of an arbitrarily connected one dimensional compressible flow network with pumping in the channels and momentum balancing at flow junctions. Program includes pressure drop calculations for impingement flow and flow through pin fin arrangements, as currently found in many air cooled turbine bucket and vane cooling configurations

    Efficacy of hepatic transplantation in patients with primary sclerosing cholangitis

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    Controlled trials to assess the therapeutic benefit of orthotopic hepatic transplantation (OHTx) for primary sclerosing cholangitis (PSC) cannot be justified in view of improvement of patient survival after this operation since 1981. However, the actual patient survival with OHTx can be compared with the Mayo model estimated survival probabilities without OHTx. This model, which encompasses physical, biochemical and histopathologic parameters of PSC, was constructed from a study of 392 conservatively treated PSC patients at five international centers in England and North America. We compared the actual survival of 216 adult patients with the diagnosis of advanced PSC who underwent hepatic replacement with the expected survival estimated by the Mayo PSC natural history model, 'the simulated control technique.' OHTx was performed at the University of Pittsburgh and Mayo Medical Center between 5 December 1981 and 26 December 1990. The mean (plus or minus standard deviation) post-OHTx follow-up period was 34 ± 25 months (range of zero to 104 months). Before transplantation, biliary or portal hypertensive operation, or both, was performed upon 104 patients. At operation, the mean age of recipients was 42.1 ± 11.3 years and the mean value of total serum bilirubin was 13.3 ± 13.0 milligrams per deciliter. Extensive septal fibrosis and cirrhosis were histologically documented in 97 percent of the patients, with splenomegaly in 63 percent. Immunosuppressive therapy was based primarily on cyclosporin in 184 recipients and FK-506 in 32. Within six months, the Kaplan-Meier survival probability after OHTx (0.89) already was higher than predicted by the Mayo model (0.83). At five years, the Kaplan-Meier actual survival with OHTx was 0.73 compared with 0.28 expected Mayo model survival. The overall increased survival rate with transplantation was statistically significant (chi-square equals 126.6; p<0.001). At all risk stratifications, OHTx significantly improved survival with a p value of 0.031 (low risk), 0.001 (moderate risk) and <0.001 (high risk). Thus, OHTx is effective therapy for PSC. Disease gravity and unsuspected cholangiocarcinoma in the excised native liver adversely influenced short and long term survival rates after transplantation, respectively

    Age-dependent resistance to Porcine reproductive and respiratory syndrome virus replication in swine

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    <p>Abstract</p> <p>Background</p> <p>Porcine reproductive and respiratory syndrome virus (PRRSV) causes a prolonged, economically devastating infection in pigs, and immune resistance to infection appears variable. Since the porcine adaptive immune system is not fully competent at birth, we hypothesized that age influences the dynamics of PRRSV infection. Thus, young piglets, growing 16-20-week-old finisher pigs, and mature third parity sows were infected with virulent or attenuated PRRSV, and the dynamics of viral infection, disease, and immune response were monitored over time.</p> <p>Results</p> <p>Virulent PRRSV infection and disease were markedly more severe and prolonged in young piglets than in finishers or sows. Attenuated PRRSV in piglets also produced a prolonged viremia that was delayed and reduced in magnitude, and in finishers and sows, about half the animals showed no viremia. Despite marked differences in infection, antibody responses were observed in all animals irrespective of age, with older pigs tending to seroconvert sooner and achieve higher antibody levels than 3-week-old animals. Interferon γ (IFN γ) secreting peripheral blood mononuclear cells were more abundant in sows but not specifically increased by PRRSV infection in any age group, and interleukin-10 (IL-10) levels in blood were not correlated with PRRSV infection status.</p> <p>Conclusion</p> <p>These findings show that animal age, perhaps due to increased innate immune resistance, strongly influences the outcome of acute PRRSV infection, whereas an antibody response is triggered at a low threshold of infection that is independent of age. Prolonged infection was not due to IL-10-mediated immunosuppression, and PRRSV did not elicit a specific IFN γ response, especially in non-adult animals. Equivalent antibody responses were elicited in response to virulent and attenuated viruses, indicating that the antigenic mass necessary for an immune response is produced at a low level of infection, and is not predicted by viremic status. Thus, viral replication was occurring in lung or lymphoid tissues even though viremia was not always observed.</p

    Tranexamic acid increases early perioperative functional outcomes after total knee arthroplasty.

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    Background: The purpose of this study was to investigate the influence of tranexamic acid (TXA) on functional outcomes in the immediate postoperative period after total knee arthroplasty (TKA). We hypothesized that the known benefits of TXA would confer measurable clinical improvements in physical therapy (PT) performance, decrease pain, and decrease hospital length of stay (LOS). Methods: We retrospectively analyzed 560 TKA patients, including 280 consecutive patients whose surgery was performed before the initiation of a standardized TXA protocol and the first 280 patients who received TXA after protocol initiation. Outcome measurements included postoperative changes in hemoglobin and hematocrit, LOS, pain scores, destination of discharge, and steps ambulated with PT over 5 sessions. Results: TXA administration resulted in less overall drops in hemoglobin ( Conclusions: It is well known that TXA reduces postoperative anemia, but this study also demonstrates that it confers early perioperative functional benefits for TKA patients. Potential mechanisms for this benefit include reduced rates of postoperative anemia and reduced rates of hemarthroses

    Genomic and evolutionary inferences between American and global strains of porcine epidemic diarrhea virus

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    AbstractPorcine epidemic diarrhea virus (PEDV) has caused severe economic losses both recently in the United States (US) and historically throughout Europe and Asia. Traditionally, analysis of the spike gene has been used to determine phylogenetic relationships between PEDV strains. We determined the complete genomes of 93 PEDV field samples from US swine and analyzed the data in conjunction with complete genome sequences available from GenBank (n=126) to determine the most variable genomic areas. Our results indicate high levels of variation within the ORF1 and spike regions while the C-terminal domains of structural genes were highly conserved. Analysis of the Receptor Binding Domains in the spike gene revealed a limited number of amino acid substitutions in US strains compared to Asian strains. Phylogenetic analysis of the complete genome sequence data revealed high rates of recombination, resulting in differing evolutionary patterns in phylogenies inferred for the spike region versus whole genomes. These finding suggest that significant genetic events outside of the spike region have contributed to the evolution of PEDV

    Post-Acute Care Payment Reform Demonstration: Final Report Volume 4 of 4

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    This is the Final Report for the Post-Acute Care Payment Reform Demonstration (PAC-PRD), authorized by section 5008 of the Deficit Reduction Act of 2005, Public Law 109-171. The report has 12 sections, which are divided into four volumes: Volume 1: Executive Summary. Volume 2: Sections 1-4 (Section 1: Introduction; Section 2: Underlying Issues of the PAC-PRD Initiating Legislation; Section 3: Developing Standardized Measurement Approaches: The Continuity Assessment Record and Evaluation (CARE); Section 4: Demonstration Methods and Data Collection) Volume 3: Sections 5-6 (Section 5: Framework for Analysis; Section 6: Factors Associated with Hospital Discharge Destination) Volume 4: Sections 7-12; References (Section 7: Outcomes: Hospital Readmissions; Section 8: Outcomes: Functional Status; Section 9: Determinants of Resource Intensity: Methods and Analytic Sample Description; Section 10: Determinants of Resource Intensity: Lessons from the CART Analysis; Section 11: Determinants of Resource Intensity: Multivariate Regression Results; Section 12: Conclusions and Review of Findings; References

    Post-Acute Care Payment Reform Demonstration: Final Report Volume 3 of 4

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    This is the Final Report for the Post-Acute Care Payment Reform Demonstration (PAC-PRD), authorized by section 5008 of the Deficit Reduction Act of 2005, Public Law 109-171. The report has 12 sections, which are divided into four volumes: Volume 1: Executive Summary. Volume 2: Sections 1-4 (Section 1: Introduction; Section 2: Underlying Issues of the PAC-PRD Initiating Legislation; Section 3: Developing Standardized Measurement Approaches: The Continuity Assessment Record and Evaluation (CARE); Section 4: Demonstration Methods and Data Collection) Volume 3: Sections 5-6 (Section 5: Framework for Analysis; Section 6: Factors Associated with Hospital Discharge Destination) Volume 4: Sections 7-12; References (Section 7: Outcomes: Hospital Readmissions; Section 8: Outcomes: Functional Status; Section 9: Determinants of Resource Intensity: Methods and Analytic Sample Description; Section 10: Determinants of Resource Intensity: Lessons from the CART Analysis; Section 11: Determinants of Resource Intensity: Multivariate Regression Results; Section 12: Conclusions and Review of Findings; References
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